from inspect import isclass from .props import props class SubclassWithMeta_Meta(type): _meta = None def __str__(cls): if cls._meta: return cls._meta.name return cls.__name__ def __repr__(cls): return f"<{cls.__name__} meta={repr(cls._meta)}>" class SubclassWithMeta(metaclass=SubclassWithMeta_Meta): """This class improves __init_subclass__ to receive automatically the options from meta""" def __init_subclass__(cls, **meta_options): """This method just terminates the super() chain""" _Meta = getattr(cls, "Meta", None) _meta_props = {} if _Meta: if isinstance(_Meta, dict): _meta_props = _Meta elif isclass(_Meta): _meta_props = props(_Meta) else: raise Exception( f"Meta have to be either a class or a dict. Received {_Meta}" ) delattr(cls, "Meta") options = dict(meta_options, **_meta_props) abstract = options.pop("abstract", False) if abstract: assert not options, ( "Abstract types can only contain the abstract attribute. " f"Received: abstract, {', '.join(options)}" ) else: super_class = super(cls, cls) if hasattr(super_class, "__init_subclass_with_meta__"): super_class.__init_subclass_with_meta__(**options) @classmethod def __init_subclass_with_meta__(cls, **meta_options): """This method just terminates the super() chain"""